This patch intends to clean up all coding style issues in InstancingTest.cpp. 1. Replace SHADER_SOURCE by std::string 2. Use (expected, actual) as the order of the parameters in ASSERT_NE 3. Replace C-style type cast operators into C++ ones. 4. Use ANGLE_GL_PROGRAM to build shader programs 5. Use constexpr when necessary 6. Other format changes done by 'git cl format' BUG=angleproject:2005 Change-Id: I37d866c5df681160a66226bf5927dd6e00a6d6b2 Reviewed-on: https://chromium-review.googlesource.com/528649 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org>